In any duplicating system, programming the duplicator to process the desired quantity of copies has presented some problems. The processing herein referred to may take the form of either producing copies or distributing copies within a printing system. This becomes a problem in systems work when numerous short run originals with different copy counts are desired to be handled. Originally, an operator was required to set the quantity for each original into the machine every minute or two between successive printing cycles. A more desirable arrangement is when the information concerning the quantities for each original or the like is set into the duplicating machine automatically, thus freeing the operator for other work.
In one prior art concept, such automatic control of the duplicating machine is accomplished by reading coded information from an original document or prepared master, before insertion into the copying cycle of a duplicating device. This is done by either moving a read head across the stationary original or moving the original past a stationary read head as the duplicating cycle is entered. U.S. Pat. No. 3,650,204 uses this concept to read quantity information by moving a read head across a stationary original.
As a practical matter, these methods required a certain degree of preprinting on the original so that registration of the information is effective. This preparing may include timing marks or other devices to indicate the areas where information will be found, and thus aid in synchronization of the machine.
There has been increased demand for the ability to program duplicating processes from information contained on an original requiring less preprocessing than formerly available. Such an original would be, for example, the result of the output from a line printer connected to a computer. Another important source of such an original is an ordinary original with the information being hand encoded. In the past, either of these possibilities would have proved rather impractical due to the difficulty of assuring proper registration of coded information applied by these means.
The registration problem may also be complicated by the desirability of elimination gating, i.e., turning on the sensing logic only when information should be within its view. Such gating is desirable so that the chance for interpreting extraneous marks on the original as encoded information will be greatly reduced. There is, moreover, a necessity for field gating which is used to classify the mark signals according to some reference significance (e.g., numerical value). The computer generated originals, to some extent, and hand encoded originals, to a much larger extent, are susceptible to somewhat random placing of the information, and, if the information should appear outside the appropriate areas as defined by such field gating or elimination gating, an incorrect instruction (such as a wrong copy count) will occur.
The effectiveness of the invention to be described depends upon the particular type of duplicating machine used. A machine in which the original is fed to, accurately positioned on, and clamped to a regularly timed moving mechanical element, particularly a machine in which there is a timed cylinder onto which the original is inserted with its lead edge at a predetermined peripheral position on the cylinder, which cylinder is revolved in the duplicating process, is exemplary. A "Multilith" Model 2750 duplicator manufactured by Addressograph-Multigraph Corporation is an example of such well-known machines.